Tides Geography - Tides

Tall sea waves caused by earthquakes below the floor of the sea are called _____.(cyclones, tsunamis, eruption)

The distance between a crest or trough is called _____ (amplitude, wave length, tide)

The vertical distance between a crest and a trough is called the _____.(wave length, amplitude, tide)

The depressed portion of a wave is called a ______. (trough, wave length, crest)

The raised up portion of a wave is called a _______ .(trough, wave length, crest)

In what way will the following depend on the tides:Going to coastal areas for trips:

In what way will the following depend on the tides:Salt Pans:

In what way will the following depend on the tides:Fishing:

In what way will the following depend on the tides:Steering a ship:

In what way will the following depend on the tides: Swimming:

Can you tell:

Answer the following of questions with the help of figure


(1) How do the tides occur?
(2) Which force is applied when the moon is closer to the earth?
(3) If it is high tide those having high tide at 0° and 180° meridian then at which meridians will low tide occur?

Explain the reasons for the generation of waves.

If at Mumbai (73° E meridian), there is high tide at 1.00 pm on Thursday, then on which other meridian will there be a high tide too? State with reasons.

If there is high tide at 7 am, find the timings of the next high and low tides on the same day at a given place.

Which factors are responsible for the occurrence of tides?

Spring tide and neap tide.

High tide and low tide:

Centrifugal force and Gravitational

Struture of the waves

Waves

Neap tide

Spring tide

Place located on the opposite meridian experiencing high or low tide will also experience high or low tide respectively.

At some places along the coast, the low lying areas turn into lagoons or marshy lands.

Tides are influenced more by the moon than the sun.

Neap tides are a little lower than average high tides.

On new moon and full moon days the tides are higher than average.

Observe the following pictures and answer the following questions given below and discuss:

(1) Do the above photographs show the same place or different places?
(2) Observe and note the spread of water seen in both the photographs.
(3) What is this natural event called?

Observe figure of neap tide and answer the following questions:

(1) Which phase of the moon does it show?
(2) What are the relative positions of the moon, the sun and the earth?
(3) What effect will it have on the tides?

Observe the activity on pages 9, 10 of the textbook & discuss the result of the activities and answer the question given below:


(1) What happened to the water in the container and the mixer?
(2) Which forces could be operating in activities listed above?
(3) In the following activities, which force is greater, centrifugal or gravitational?

Observe the activity on pages 9, 10 of the textbook & discuss the result of the activities and answer the question given below:


(1) In which direction will the piece of chalk fall?
(2) Where did the water in the glass show a bulge?
(3) What effect did the movement have on the things attached to the keyring?

Describe the positive and negative effects of tides:

Occurrence of tides:

Neap tide:

Springtide:

The structure of a wave:

Distance between two successive crests or troughs.

Type of tide occuring when sun and the moon are at right angles to each other.

Type of tide occuring on full moon day.

Place where tsunami waves were generated in 2004.

Tall waves caused by earthquakes in the shallow waters near the coast, which are very destructive.

Generation of waves is a natural and regularly occurring phenomenon.

The tides worsen the maintaining of mangroves and the coastal biodiversity.

The tides clean the waste and hence the coastal areas become clean.

Tides occur due to the relative positions of the moon, the sun and the earth.

When there is high tide at 0° meridian, the 180° meridian also experiences high tide.

At every ______ a cycle of high tide and low tide gets completed.

On new moon and full moon days, the gravitational pull of the sun and the moon acting the ______ direction.

On the days of the first and the third quarter, the high tide is at its _____.

The meridians that are at right angles to those having high, tide will experience tide _______.

Any object on the surface of the earth remains at the place due to the ______ force.